Copolymer, a process for producing the same and an electroluminescent element using the same

Abstract

A novel copolymer affording a highly efficient electroluminescent element by the use of which the movement of electric charge occurs very efficiently and a full color luminescence is possible, a process for producing the same and an electroluminescent element, are provided, which copolymer is prepared by copolymerizing N-vinylcarbazole as an electron-transporting compound with a specified cumarin derivative as a luminescent compound; which process comprises copolymerizing a specified quantity of a specified cumarin derivative with a specified quantity of N-vinylcarbazole in the presence of a polymerization initiator or a catalyst; and which electroluminescent element is prepared by using a thin film obtained from the copolymer.

What we claim is: 
     
       1. A copolymer consisting of repetition units expressed by the formula (1) and repetition units expressed by the formula (2), the content of the repetition units (1) in the total repetition units being 0.01 to 50% by mol, and the weight average molecular weight calculated in terms of polystyrene measured according to gel permeation chromatography being 1,000 to 1,000,000: ##STR8## in the formula (1), R 1  to R 5  each independently being chosen from the group consisting of hydrogen, fluorine, alkyl group, alkoxy group, dialkylamino group, alkanoyloxy group, alkyloxycarbonyl group, aryl group, cyano group, alkanoyl group or trifluoromethyl group; X representing O or NY (wherein Y represents hydrogen, alkyl group or aryl group); n representing 1 or 2; and R 6  representing hydrogen or methyl group. 
     
     
       2. A copolymer according to claim 1, wherein said repetition units of the formula (1) and the formula (2) are arranged randomly.